In recent years, various broadcast services such as television broadcasting and Internet broadcasting have become widely available. In these broadcast services, individual broadcast stations sequentially broadcast a large number of content data (program data) in an order according to a broadcast schedule. Viewers can select one of a large number of broadcast stations which is broadcasting program data in which the viewer takes an interest, that is, one of a large number of channels on which the program data is being broadcast.
An electronic program guide (EPG) is known as a technique to provide information about programs to viewers.
Moreover, techniques have started to be developed which involve counting the numbers of messages posted on a site on the Internet and transmitting the results of evaluation of the programs based on the numbers, to the viewers' terminals.
However, the method of evaluating the programs using the numbers of messages is based on the assumption that the number of messages vary significantly depending on the contents of the programs. When the numbers of messages do not substantially vary, the viewers' reactions may fail to be reflected in the results of evaluation.